In the metals industry, it is often desirable to be able to mark the surface of newly rendered metal pieces for identification purposes.
In order to avoid possible confusion as to the identity of freshly rendered metal pieces (such as slabs, coils, plates, blooms, rounds, pipes, billets, bars and structural members), it is most desirable to be able to mark such pieces even when they are still hot from rendering or working operations.
One of the methods of marking new metal pieces is to do so with non-contact methods involving marking inks. Naturally, their are problems associated with the use of marking inks on metal surfaces that are at temperatures measured in thousands of degrees. Such surfaces are highly reactive to certain chemical species, and it is often difficult to have inks adhere to such surfaces without being subject to flaking off particularly upon cooling, causing the metal surface to lose its identification. For this same reason, it is desirable that the inks be weatherable over rather long periods of time (i.e., up to three years) as metal products are often exposed to the elements.
Inks of this general type should have high visibility and legibility, so that they may be easily read from the metal surface, even when soiled or partially corroded. It is also advantageous that such inks have good impact resistance, abrasion resistance, thermal shock resistance and workability characteristics.
Also, because such inks must be amenable to application by automated spray equipment, it is also advantageous to create such inks that offer appropriate flow characteristics so as to be applicable through spray jets. It is also advantageous to produce inks that may be use with laser marking machines to form a background coating for laser marking.
In order to solve these problems, it was desired to create a water-based ceramic marking ink to offer the metals and other industries materials that can be used to identify metals and other materials at ambient temperatures as well as temperatures in excess of 2300.degree. F.
The invention covers an advanced group of ceramic inks formulated to adhere to metals and other materials over a wide range of temperatures. The inks can be sprayed, brushed or flow coated to the various substrates. The inks will dry to a hard, legible and durable identification or coating that will accept laser markings or other markings. The present invention may be used with the technologies described in U.S. Pat. Nos. 5,055,137 and 4,741,775 to Holcombe, Jr., et al.; U.S. Pat. Nos. 4,883,291 and 5,119,109 to Robertson; and U.S. Pat. No. 4,985,715 to Cyphert et al.; all of which are incorporated herein by reference.
In view of the present disclosure or through the practice of the invention, other advantages may become apparent.